<template>
  <div>{{ readersNumber }} {{ book }}</div>
</template>

<script lang="ts">
  import { ref, reactive } from 'vue'

  export default {
    setup() {
      const readersNumber = ref(0)
      const book = reactive({ title: 'Vue 3 Guide' })

      // 暴露给模板
      return {
        readersNumber,
        book
      }
    }
  }
</script>
